A power distribution transmission unit with a mechanical and a hydraulic power branch is known from DE 103 22 233 A1. The hydraulic or hydrostatic power branch is, in each case, connected by a shaft to the mechanical power branch. During the operation of the power distribution transmission unit, in order to substantially diminish the transfer of oscillations that occur in the area of the hydrostatic power branch into the transmission housing and into the mechanical power branch, damping elements are provided in the area of the connection point of a hydraulic motor with a hydraulic pump of the hydrostatic power branch, by which the motor and the pump are fixed in the transmission housing with damping. By virtue of the said damping elements, the hydraulic motor and the hydraulic pump are allowed some freedom of movement within the elastic range of the damping elements.
Any axial offset between the hydrostatic power branch and the mechanical power branch, that occurs due to the said movement, is compensated by a shaft that connects the hydrostatic power branch with the mechanical power branch, the said shaft having in its connection area to the hydrostatic power branch and also in its connection area to the mechanical power branch crown bevel gearing, in each case.
The disadvantage of this, however, is that the shaft length required for compensating the axial offset between the mechanical and the hydrostatic power branches of the power distribution transmission units causes the power distribution transmission unit to occupy substantial axial space.
From DE 10 2006 052 410 A1, a stub shaft is known, which connects a drive input gear rotationally fixed to a camshaft of an internal combustion engine. The stub shaft fits into the drive input gear and the camshaft, in each case, via a double crown bevel gear, whereby a large offset between the gear and the camshaft can be compensated with a stub shaft of a short length.
DE 10 2006 025 347 B3 describes a hydraulic module with two integrated inclined disks or inclined-axis gears for hydrostatic-mechanical power distribution transmission units, such that in the area of driveshafts each of which is formed with external teeth in a connection area with a mechanical power branch of a power distribution transmission unit, the hydraulic module can be connected to the mechanical power branch of the power distribution transmission unit.
By means of the external teeth of the driveshaft, deflections in the area of a hydraulic motor or a hydraulic pump of the hydraulic module cannot be compensated to the same extent as in the two systems described above and know from the prior art. Even a connection of the hydraulic module to the mechanical power branch of a power distribution transmission unit, corresponding to that described in DE 103 22 233 A1 or DE 10 2006 052 410 A1, does not reduce the axial fitting space required for the power distribution transmission unit to the desired extent.